Strapping tools



Sept. 15, 1964 Filed Jan. 23, 1963 K. J. HALL STRAPPING TOOLS 3 Sheets-Sheet 1 Attorney Sept. 15, 1964 K. J. HALL STRAPPING TOOLS 3 Sheets-Sheet 2 Filed Jan. 23, 1963 Sept. 15, 1964 K. J. HALL 3,148,862

- STRAPPING TOOLS Filed Jan. 23, 1963 s Sheets-Sheet a InvenhtM 2 34M A tlorney United States Patent 3,148,862 STRAPPING TOOLS Kenneth J. Hall, Stechford, Birmingham, England, assignor to Fredk. A. Power & Sons Limited, Birmingham, England, a British company Filed Jan. 23, 1963, Ser. No. 253,311 Claims priority, application Great Britain, Feb. 13, 1962, 5,399/62 4 Claims. (Cl. 254-51) This invention relates to a strapping tool of the kind which is used for the securing of the ends of a wire, strap or band which has been wrapped round a package such as a box, crate, carton or the like. The tool serves to secure the two ends of the wire together such as by twisting or forming a seal. The present invention is partly, though not exclusively, concerned with a tool in which the wires are laid side by side in a twister pinion 'which is then rotated to twist the wires together and secure them.

The expression wire, as used herein, is intended to be taken in the generic sense as including not only round wire but also half round wire, ribbon, strip or the like.

In Lhe use of such a tool one end of the wire is gripped in the tool and the other end of the wire has to be drawn taut so that it is gripped under tension whilst the securing or tying operation is taking place and the object of the invention is to provide an improved gripping and tensioning device for such a tool which will more satisfactorily apply the tension, hold the wire under tension while being secured, and then rapidly release the wire, than with devices provided hitherto.

According to the invention there is provided in or for a strapping tool of the kind referred to, a gripping and tensioning device comprising, a body which is fixed rigidly in relation to the strapping tool, first and second wedgeshaped gripping members mounted loosely upon said body and adapted to grip the wire by means of their operative faces at spaced positions along the wire, said first gripping member being engaged by a movable abutment member which can be moved relatively to the body to force the first gripping member into engagement with the wire, and said second gripping member being engaged by a fixed abutment member, which is fixed in relation to the body, to hold said second gripping member in engagement with the wire when tension is applied to the wire.

The movable and fixed abutment members above referred to, may comprise rollers, and the movable abutment member may be a roller which is mounted upon a block, said block being slidable upon the body of the device.

The sliding block may have a platform upon which the wire is laid and between which, and the wedge member, the wire is gripped.

Such sliding block may be mounted to slide along a pair of parallel rods fixed in the body and an actuating handle may be pivotally mounted on the body with part thereof engaging the sliding block to provide the movement thereof.

The invention is illustrated in the accompanying drawings wherein:

FIGURE 1 is a plan view,

FIGURE 2 is a front view of the gripping device, and,

FIGURE 3 is a section on line 33 of FIGURE 1.

In the embodiment shown in the drawings the gripping device G is formed as a part of the complete strapping tool S and is conveniently secured to a rigid base member B formed as an extension to one side of the body of the strapping tool.

The body of the gripping device comprises an upstanding rear Wall which at its lower end has a projecting 3,148,862 Patented Sept. 15.,- 1964 flange 11 by means of which the body can be secured to the extension part 12 of the strapping tool, and oii its front face this rear Wall 10 has projecting therefrom two brackets 13 and 14, one disposed near each end of the wall.

The bracket 13 at one end is provided with upper and lower circular openings and similar openings are provided in register with these openings in the bracket 14 at the other end, and a pair of rods 16 extend between the brackets, being mounted at their ends in the registering holes in the brackets.

The bracket 13 which is closest to the strapping tool is simply a supporting bracket for the ends of the two rods 16 and the other bracket 14 at the other end of the wall 10 is formed as a mounting block which has a projecting platform 17 at its lower edge upon which is disposed the second wedge-shaped gripping member 18, and this gripping member has an operating face 51 which is preferably serrated or toothed, and an inclined face 54 on the opposite side from the operating face, such inclined face being inclined towards the operating face 51 in the direction towards the strapping tool.

The abutment member, which engages this inclined face of the second gripping member 17, is in the form of a roller 19 mounted upon a pivot pin 55 fixed in the rear wall of the body, and the wedge-shaped gripping member 18 has a blind hole 20 extending inwardly from its larger end in which engages the one end of a spring 56, which at its outer end bears against an inturned portion 21 of an inner cover plate 22 which is fixed at 23 upon the rear wall it) of the body and extends downwardly so as to cover the roller 19 and also cover part of the gripping member 18, but leaving a gap 58 between the lower edge of the cover 22 and the platform 17 through which the wire can be introduced and is ejected when released.

An outer cover .plate 50 is pivotally mounted at 57 upon the body and has an inturned portion 52 extending across the thin end of the wedge shaped gripping member 18, and another inturned part 53 which engages the outside of the bracket 14.

The first gripping member 24 is also Wedge shaped and is loosely mounted in a sliding block 25 which has upper and lower holes extending therethrough, and by means of which the block 25 is slidably mounted upon the said two parallel rods 16 by threading the rods through the holes of the block, so that the block is capable of sliding in the direction away from the first mentioned bracket 13 and towards the fixed bracket 14 at the other end and thereafter in the reverse direction.

On its rear face this block 25 has an elongated slot 26 in which engages a pivot roller 27 provided at the lower end of an actuating handle 28, and this handle extends down in the space between the rear face of the block 25 and the rear wall 10 of the body and is pivotally mounted upon a pivot post 29 fixed in the rear wall of the body. The actuating handle 28 extends upwardly above this pivot post 29 and is provided with a suitable knob 30, and it is also spring loaded in the direction which causes the sliding block to be forced against its adjacent bracket; such spring loading is by means of coiled spring 31 connected between a post 32 fixed in the back of the rear wall of the body and a post 33 fixed in the actuating handle at a position above the pivot post of the actuating handle.

The first wedge-shaped gripping member 24 is mounted upon the sliding block and is of similar construction to the second gripping member above described; and the sliding block also has an outwardly projecting platform 34 upon which the wire is placed, this platform and also the platform on the fixed block, being inclined downwardly and outwardly to facilitate insertion of the Wire.

The first gripping member is also provided with a spring which engages an inturned portion 35 of a cover plate 36 fixed upon the sliding block and of the same construction as the cover plate 22 above described in connection with the fixed block.

The actuating member which engages the inclined face of the first gripping member 24 is also a. roller 37 mounted upon a pivot post which is secured at 38 onto the rear part of the sliding block.

With this arrangement when the end of the wire is slidden up the two inclined platforms it can be forced underneath the two gripping members which can both move upwards against their respective springs and thus, when the actuating handle is moved against its loading spring, it causes the sliding block 25 to move in the direction away from the strapping tool, and the abutment roller 37 of the sliding block, by engaging the one gripping member 24, forces this down into gripping engagement with the wire and pulls the wire taut around the package. This longitudinal movement of the wire when being pulled taut causes the wire to slip under the second gripping member 18 but by virtue of the engagement of the fixed abutment roller 19 with the second gripping member 18 the wire cannot move back in the rearward direction. Thus the second gripping member 18 acts positively to hold the wire under tension when the actuating handle 28 is released and its spring loading brings it back to the original position and thereby moves the sliding block 25 towards the strapping tool for engagement with its associated bracket 13.

When the wire has been cut and the tension released the free portion of wire can then be easily released from the second gripping member 18 and ejected from the gripping device.

It is convenient to provide means for preventing either of the gripping members 18, 24 from becoming jammed between its abutment member 19 or 3.7 and its platform 17 or 34 such as to make it ditficult to introduce the wire between a gripping member and its platform. The small end of the second gripping member 18 projects beyond its platform 17 towards the inturned portion 52 of the outer cover plate 58 and abuts against that portion 52 whereby, when there is no wire on the platform 17, the gripping member 18 is prevented from moving towards the strapping tool to the extent necessary for it to jam between its abutment roller 19 and platform 17. Similarly, when the sliding block 25 is nearest the strapping tool, the smaller end of the first gripping member 24 abuts against the associated bracket 13 to prevent the gripping member 24 from moving in the block 25 to a position in which it might jam between its abutment roller 37 and platform 34.

What I claim then is:

1. In a strapping tool, a gripping and tensioning mechanism comprising a rigid body stationary on and extending from the tool, a first clamp stationary on the body, parallel guides extending from the first clamp towards the tool, a second clamp in sliding engagement With the guides, and an actuating handle engaging the second clamp and pivotal to reciprocate the second clamp on the guides, each clamp comprising a wire-receiving platform, an abutment member fixed relatively to and spaced from the platform and a Wedge-shaped gripping member located loosely between the abutment member and the platform, each gripping member having an operative face presented towards its associated platform and an inclined face which is presented towards its associated abutment member and which is inclined towards its operative face in the direction of the tool, and each gripping member being movable towards the tool into the space between the associated abutment member and platform to engage its inclined face with the abutment member and be thereby urged towards the platform to bring its operative face into clamping cooperation with the platform and being movable in the opposite sense to bring its operative face out of clamping co-operation with the platform.

2. In a strapping tool, a gripping and tensioning mechanism as claimed in claim 1, in which each abutment member is a roller.

3. in a strapping tool, a gripping and tensioning mechanism as claimed in claim 1, in which there is movably mounted on the first clamp a projection extending between the second clarnp and the Wedge-shaped gripping member of said first clamp, said projection being movable in the direction away from the strapping tool to engage and displace the last mentioned gripping member in the sme direction.

4. in a strapping tool, a gripping and tensioning mechanism as claimed in claim 1, in which there is a projection stationary on said body and extending between the second clamp and the strapping tool to be engageable by the second clamp to determine the limit of its movement towards the strapping tool, and the end of the gripping member of the second clamp projects from the second clamp towards the strapping tool to be engaged by the projection before the second clamp engages the projection.

References Cited in the file of this patent UNITED STATES PATENTS 752,621 Huerth et al Feb. 16, 1904 1,114,832 Whitney Oct. 27, 1914 1,806,844 'Dennis May 26, 1931 1,993,755 Spoor Mar. 12, 1935 2,810,573 Nadel Oct. 22, 1957 2,845,250 Ball -Q July 29, 1958 2,864,582 Hall Dec. 16, 1958 

1. IN A STRAPPING TOOL, A GRIPPING AND TENSIONING MECHANISM COMPRISING A RIGID BODY STATIONARY ON AND EXTENDING FROM THE TOOL, A FIRST CLAMP STATIONARY ON THE BODY, PARALLEL GUIDES EXTENDING FROM THE FIRST CLAMP TOWARDS THE TOOL, A SECOND CLAMP IN SLIDING ENGAGEMENT WITH THE GUIDES, AND AN ACTUATING HANDLE ENGAGING THE SECOND CLAMP AND PIVOTAL TO RECIPROCATE THE SECOND CLAMP ON THE GUIDES, EACH CLAMP COMPRISING A WIRE-RECEIVING PLATFORM, AN ABUTMENT MEMBER FIXED RELATIVELY TO AND SPACED FROM THE PLATFORM AND A WEDGE-SHAPED GRIPPING MEMBER LOCATED LOOSELY BETWEEN THE ABUTMENT MEMBER AND THE PLATFORM, EACH GRIPPING MEMBER HAVING AN OPERATIVE FACE PRESENTED TOWARDS ITS ASSOCIATED PLATFORM AND AN INCLINED FACE WHICH IS PRESENTED TOWARDS ITS ASSOCIATED ABUTMENT MEMBER AND WHICH IS INCLINED TOWARDS ITS OPERATIVE FACE IN THE DIRECTION OF THE TOOL, AND EACH GRIPPING MEMBER BEING MOVABLE TOWARDS THE TOOL INTO THE SPACE BETWEEN THE ASSOCIATED ABUTMENT MEMBER AND PLATFORM TO ENGAGE ITS INCLINED FACE WITH THE ABUTMENT MEMBER AND BE THEREBY URGED TOWARDS THE PLATFORM TO BRING ITS OPERATIVE FACE INTO CLAMPING COOPERATION WITH THE PLATFORM AND BEING MOVABLE IN THE OPPOSITE SENSE TO BRING ITS OPERATIVE FACE OUT OF CLAMPING CO-OPERATION WITH THE PLATFORM. 